The number of children with autism has spiked in the past two years, according to a new report by the Centers for Disease Control and Prevention (CDC). According to the report, one in 68 U.S. children has an autism spectrum disorder (ASD), a 30 percent jump from 1 in 88 reported two years ago.
The CDC analyzed the health and educational records of 8-year-old children in 11 states: Alabama, Wisconsin, Colorado, Missouri, Georgia, Arkansas, Arizona, Maryland, North Carolina, Utah, and New Jersey. More than 5,300 children are represented in the data. The rates of autism ranged from a low of 1 in 175 children in Alabama to a high of 1 in 45 kids in New Jersey, according to the report.
The report reaffirms the disproportionate effects of autism on boys, estimating that 1 in 42 boys has autism, four times higher than the rate for girls.
In a press statement, Coleen Boyle, director of the CDC’s National Center on Birth Defects and Developmental Disabilities, said the CDC looks at all of the characteristics of ASD, including the age at which the condition is identified.
“We look at their earliest diagnosis," she said. "We look at co-occurring conditions that these children might have, other developmental disabilities, whether or not they have intellectual disability, so essentially their IQ."
Autistic Children Have Average or Above Average IQs
The largest increase in diagnoses was among children who have average or above-average intellectual ability, says the CDC. In fact, the report found that nearly half of children with an autism spectrum disorder have average or above-average intellectual ability—an IQ above 85—compared with one-third of children diagnosed with ASD a decade ago.
Pointing out that the report is not designed to show why more children are being diagnosed with autism, Boyle said that greater awareness in identifying children with autism has likely contributed to the rising rates of ASD diagnosis.
The report also found that the average age of diagnosis for children with autism is older than four, even though autism can be diagnosed as early as two years of age.
Dr. Max Wiznitzer, a pediatric neurologist at Rainbow Babies and Children's Hospital in Cleveland who diagnoses and treats children with autism, told CNN, “We need to continue our efforts to educate the health care community and general public to recognize the developmental problems associated with ASD and other developmental disorders at the earliest age possible, so that intervention can be initiated, bad habits can be avoided, and families will know what's wrong with their child."
Autism Begins in the Womb
Meanwhile, in a separate study, researchers at the University of California, San Diego School of Medicine and the Allen Institute for Brain Science have found new evidence that autism begins during pregnancy.
In the study, published in the New England Journal of Medicine, the researchers analyzed 25 genes in preserved brain tissue from children with and without autism. These included genes that serve as biomarkers for brain cell types in different layers of the cerebral cortex, genes implicated in autism, and several control genes.
One of the study researchers, Ed Lein, Ph.D., of the Allen Institute for Brain Science in Seattle, Wash. told Healthline, “We found evidence for a disruption of the young autistic neocortex in the regions responsible for such abilities as language and comprehension of social cues that strongly suggests an early origin in prenatal life. Specifically, we observed small 'patches' of cortex in which the typical layers are disorganized and genes used by cells in those layers are misregulated.”
Lein said his team was surprised to find commonalities in the brains of the autistic children they studied. “Given the great variation between autistic individuals in their genetics and their symptoms, the finding of a common feature was quite surprising," he said. "While this small study needs to be replicated on a larger scale, the implication is that many genes can converge on a similar process, namely early development of the neocortex, which is responsible for many of the cognitive capabilities affected in autism.”
Lein added that the researchers were also surprised to find locally affected regions of the cortex, as opposed to widespread genetic disruption. “Since we found these patches by examining very small regions, we assume these patches are spread over large parts of the cortex, and it may be that the frequency and exact locations of patches may be related to the functions disrupted in individuals with autism,” he said.
In offering advice to expectant parents and parents who may be worried that their children are at risk for developing autism, especially in the wake of the CDC report, Lein told Healthline, “Our findings provide additional evidence for an early origin of autism, but do not speak to its causes. Further research is needed to better understand the mechanisms and find the means for earlier diagnosis.”